Hydraulic Sleeve with Early Release Prevention

ABSTRACT

A downhole window tool includes an internal sleeve slidably received within an outer housing. The sleeve and outer housing may have windows that selectively align or the sleeve may move out of alignment with the window to allow fluid passage through a window. Sleeve movement within the housing is controlled by inserting a dart or plug in the interior of the sleeve to allow pressure to act on the plug or dart to move the sleeve a set amount to open the lateral window. A shear pin or other device may be used to control the amount of force necessary to open the window and further ensure unintended opening of the lateral window. The use of the removable dart or plug both prevents unintentional forces from opening the window and increases the amount of throughput through the sleeve as compared to when valve structure is installed within the tool.

This application claims the benefit of U.S. Provisional Application 61/381,509, filed Sep. 10, 2010, entitled Hydraulic Sleeve with Early Release Prevention, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. FIELD OF THE INVENTION

The present application relates to a tool having a lateral window in the tool and a system for opening the lateral window and preventing unintended opening of the window.

2. DESCRIPTION OF THE PRIOR ART

Downhole tools must be activated remotely to avoid having to trip the tools hundreds or thousands of feet out of the hole to change their function or setting. There are a few ways currently used to address a particular tool. These include a combination of lifting (“tension”), setting down (“compression”), and rotating. The use of J tools, shear pins, springs and packers with these motions help bring about desired changes in the tools and can be used to sequentially or individually address multiple downhole tools. In recent decades, balls having a specified diameter have been used to drop down tubing and through or into a tool to cause a particular action or to block a particular passage.

The present invention shows in a preferred embodiment using an insertable plug or dart to open a lateral window, wherein when said dart or plug is not inserted pressure flow cannot unintentionally open the lateral window. A shear pin or other device may be used to control the amount of force required to open the lateral window and to pin the window in place when not needed.

None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.

SUMMARY OF THE INVENTION

The present invention uses an internal sleeve slidably received within a tubular housing. The sleeve and outer housing may have windows that selectively align or the sleeve may move out of alignment with the window to allow fluid passage through a window. Movement of the sleeve within the housing is controlled by inserting a dart or plug in the interior of the sleeve to allow pressure to act on the plug or dart to move the sleeve a set amount to open the lateral window. A shear pin or other device may be used to control the amount of force necessary to open the window and further ensure unintended opening of the lateral window. The use of the removable dart or plug both prevents unintentional forces from opening the window and increases the amount of throughput through the sleeve as compared to when valve structure is installed within the tool.

Accordingly, it is a principal object of a preferred embodiment of the invention to provide a downhole tool that can be activated and deactivated by a plug or dart inserted within the tool.

It is another object of the invention to provide a down hole tool that has a shear pin to prevent unintended operation of the device.

It is a further object of the invention to provide a downhole tool having an activation device such as a dart or plug that can be inserted and removed to limit flow interruption through the device.

Still another object of the invention is to provide a downhole tool that has a number of window tools that can be activated in any order by inserting a dart or bridge plug at the desired tool to activate that tool and only that tool.

It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.

These and other objects of the present invention will be readily apparent upon review of the following detailed description of the invention and the accompanying drawings. These objects of the present invention are not exhaustive and are not to be construed as limiting the scope of the claimed invention. Further, it must be understood that no one embodiment of the present invention need include all of the aforementioned objects of the present invention. Rather, a given embodiment may include one or none of the aforementioned objects. Accordingly, these objects are not to be used to limit the scope of the claims of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary embodiment of a downhole tool showing at least one aspect of the invention in the closed position.

FIG. 2 is an exemplary embodiment of a downhole tool showing at least one aspect of the invention in the open position.

FIG. 3 is a diagrammatic view of a system according to at least one aspect of the present invention.

Similar reference characters denote corresponding features consistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The present invention according to at least one aspect is to a downhole, window tool 10 having a device for activating a lateral window on the tool in preparation for well processes such as fracturing and production without having to run the tool out of the hole to change the mode of the tool.

The downhole window tool 10 is designed to be installed on a drill string 60 or similar device. As shown in FIG. 3, a number of the tools 10 may be installed and separated a large distance apart by spacers 62 or the like of sufficient length so that when installed the opening 18 of each window tool 10 aligns with an opening 64 of the well casing 66. While only two tools are shown, any number of tools may be used. The drill string and components may be connected at the top to a tank 68 at a location above the surface to contain produced fluids.

As shown in FIGS. 1 and 2, an individual downhole, window tool may comprise an outer housing 12, which is substantially tubular in shape. An upper sub 16 and lower sub 14 may be connected at either end of the tool by threads, screws, shear pins or the like. The outer housing has an opening 18, which is preferably formed as a number of slots or openings around the circumference of the housing but may be one continuous opening. The purpose of these openings is to allow fluid communication between an area within the housing and the area outside of the housing when the opening 18 is uncovered by an internal sleeve 20. The internal sleeve is arranged to slide within the outer housing 12 between a closed position as shown in FIG. 1 and an open position as shown in FIG. 2. A stop 22 may be installed in the outer housing 12 to control the distance that the internal sleeve may slide. The slide may be anchored by a button or detent 26 extending from the slide being located in the outer housing. The sleeve 20 below the lower surface of the slide will prevent the stop button from sliding out of the housing thus will maintain the stop in place. The ends of the stop may provide an upper and/or lower limit to the sliding motion of the sleeve. The stop may alternatively be used to connect the opposite ends of the housing, but preferably the housing is made of a one piece unit with the stop installed between the housing and the sleeve.

In the preferred embodiment, the sleeve is arranged within the outer housing to slide between the closed position and the open position. To prevent unintentional operation of the sleeve, the sleeve may be pinned in the closed position by a shear pin 24 or the like. The shear pin will shear under a preselected pressure to allow the sleeve to slide to the open position. The present design as will be discussed hereinunder further prevents unintentional opening by reducing the number of pressure surfaces within the window tool that could be acted upon to open the window (i.e., “activate the sleeve”). Previous designs such as copending application 12/980,021, filed Dec. 28, 201 entitled “Step Ratchet Fracture Window System”, which is incorporated herein by reference, shows a ball valve dropped through the tool to plug a valve seat to operate the sleeve movement under fluid pressure. Because the ball is of a very limited size compared to the diameter of the housing, the valve seat itself blocks a great deal of flow through the tool, which could potentially cause the sleeve to prematurely move. Additionally, the valve seat restriction acts to restrict the total amount of flow through the tool from lower window tools and thus may reduce the production flow through the drill string.

The present invention by contrast uses a removable bridge plug 30 or dart to activate the tool. A recess, internal flange or abutment in the sleeve may be used to capture the plug or dart when installed. The plug or dart acts to block flow through the tool allowing pressure to build up until it exceeds the shear point of the shear pin holding the sleeve in place. The fluid pressure then acts to move the sleeve away from the window 18 to allow communication through the window to an outer zone or further tubing, etc. The walls of the recess retaining the plug cause the sleeve to travel with the plug instead of allowing the plug to slide along the sleeve. The walls allow forces to be transferred from the plug (or dart) to the sleeve.

The use of a dart or bridge plug also allows easier selection of the tool on which to operate. A casing collar locator tool (“CCL”) or similar device may be used to track the depth of a tool or portion of a tool. By tracking the depth of windows in the down hole and the depth of the bridge plug or dart, the dart may be place precisely into a desired window tool and inflated or otherwise fixed in place in a particular window tool. Subsequent pressurization of the interior of the window tool from the surface will cause the pressure to act on the bridge plug or dart and thus on the sleeve, shearing the pin 24 and moving the sleeve to the open position. The sleeve will then stay open until processing is completed and the tool removed to the surface. The plug or dart may be removed if flow is desired to a location below the tool, such as to a lower tool using a known bridge plug or dart removal tool.

While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and/or adaptations of the invention following in general the principle of the invention and including such departures from the present disclosure as come within the known or customary practice in the art to which the invention pertains and as maybe applied to the central features hereinbefore set forth, and fall within the scope of the invention and the limits of the appended claims. It is therefore to be understood that the present invention is not limited to the sole embodiment described above, but encompasses any and all embodiments within the scope of the following claims. 

1. A method of selectively uncovering a lateral opening in a downhole window tool comprising: providing an outer housing 12 having a generally tubular shape and a first lateral opening therethrough; providing a tubular sleeve coaxial with and slidably received within said outer housing, said tubular sleeve having a second lateral opening therethrough; installing said tubular sleeve in a first position within said outer housing such that said first lateral opening is out of alignment with said second lateral opening whereby there is no fluid communication through the first and second later openings between a first zone defined within said tubular sleeve and a second zone outside of said outer housing; installing said outer housing on a drill string and lowering said drill string within a well bore; lowering a bridge plug through said drill string to said first zone until said bridge plug abuts an abutment on an inner wall of said tubular sleeve; pressurizing said first zone through said drill string, whereby pressure on said bridge plug acts on said abutment to move said inner sleeve relative to said outer housing from said first position to a second position wherein said first and second lateral openings are aligned to provide fluid communication between said first and second zones.
 2. The method of claim 1, wherein installation of the tubular sleeve in the first position includes affixing the tubular sleeve in place by shear pinning the tubular sleeve to the outer housing.
 3. The method of claim 1, wherein the outer housing is connected to said drill string by an upper sub.
 4. The method of claim 1, wherein said bridge plug completely blocks fluid flow through to a lower end of said tubular sleeve.
 5. A method of selectively uncovering a lateral opening in a downhole window tool comprising: providing an outer housing having a generally tubular shape and a first lateral opening therethrough; providing a tubular sleeve coaxial with and slidably received within said outer housing, said tubular sleeve having a second lateral opening therethrough; installing said tubular sleeve in a first position within said outer housing such that said first lateral opening is out of alignment with said second lateral opening whereby there is no fluid communication through the first and second later openings between a first zone defined within said tubular sleeve and a second zone outside of said outer housing; installing said outer housing on a drill string and lowering said drill string within a well bore; lowering a dart through said drill string to said first zone until said dart bridge plug abuts an abutment on an inner wall of said tubular sleeve; pressurizing said first zone through said drill string, whereby pressure on said dart bridge plug acts on said abutment to move said inner sleeve relative to said outer housing from said first position to a second position wherein said first and second lateral openings are aligned to provide fluid communication between said first and second zones.
 6. The method of claim 1, wherein installation of the tubular sleeve in the first position includes affixing the tubular sleeve in place by shear pinning the tubular sleeve to the outer housing.
 7. The method of claim 1, wherein the outer housing is connected to said drill string by an upper sub.
 8. The method of claim 1, wherein said dart bridge plug completely blocks fluid flow through to a lower end of said tubular sleeve.
 9. A method of selectively uncovering a lateral opening in a downhole window tool comprising: providing an outer housing on said downhole window tool having a generally tubular shape and a first lateral opening therethrough; providing a tubular sleeve coaxial with and slidably received within said outer housing, said tubular sleeve having a second lateral opening therethrough; pinning said tubular sleeve in a first position within said outer housing such that said first lateral opening is out of alignment with said second lateral opening whereby there is no fluid communication through the first and second later openings between a first zone defined within said tubular sleeve and a second zone outside of said outer housing; lowering said downhole window tool on a drill string drill string within a well bore; pressurizing said first zone to cause flow from above said first zone through said tubular sleeve to an area below said first zone; lowering a bridge plug through said drill string to said first zone until said bridge plug abuts an abutment on an inner wall of said tubular sleeve; pressurizing said first zone through said drill string, whereby pressure on said bridge plug acts on said abutment to move said inner sleeve relative to said outer housing from said first position to a second position wherein said first and second lateral openings are aligned to provide fluid communication between said first and second zones; whereby further pressurization of said first zone causes flow to flow from above first zone through said first and second lateral opening to said second zone.
 10. The method of claim 1, wherein pinning the tubular sleeve in the first position includes affixing the tubular sleeve in place by shear pinning the tubular sleeve to the outer housing.
 11. The method of claim 1, wherein the outer housing is connected to said drill string by an upper sub.
 12. The method of claim 1, wherein said dart bridge plug completely blocks fluid flow through to a lower end of said tubular sleeve. 